Speed-change mechanism



April 5,. 1921.

w. M. MITCHELL.

SPEED CHANGE MECHANISM Filed Sept. 17. 1925 `4 sheets-sheet 1 .glv'ENT'OR M, M. Mft :Hell 8%@ April 5;1927. WM Mm'ZHELL 1,623,695 SPEED GHNGE MECHANISM I piled sept, 17.1925y 4 sneeps-vsneena A g N :s

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s 3 ma am i as l g cn g L \t v if@ I I m \/\f( 3f 5 E or' el n o K R -WTNESSES l -wMMa/ll ArroaNsYs W M MITCHELL SPEED CHANGE MECHANISM Flled Sept 17, 1925 April 5, 1927.

5 1927. April w. M. MITCHELL l SPEED C HANGE yMEGI'INISM I 4 Sheets-Sheet 4.

Filed vSepl. 17, 1925 ATTORNEYS Cil sit'on :et parts when in highgear.

Parentle 1927-. i

WILLIAM OI'EHGRENADA, MISSISSIPPI.

Application filed September yl'lhi-sninvention relates f to improvements in inecliaiiismvfzconinionly v'referred to as gear shiittfin-eehanisin, andl it-consists oi the con strnctionsy coinbinatioi'is and arrangements herein described and claimed. Ani objectot' thel invention is to provider a leed changer,mechanism VAor` gear shifter 5esigiied suche `manner that shifting may be done iionilone speed to another While the motor vehicle .or othermachinery is in nio-V tfioii and `:Without requiring f that the :engine be disconnected or released, as is now the custom. i711" le f V1v l i v- A.Another objieotoffthe inventionisito provdepainiechanisni of the character described inmvliichzthespeed changes are made byva novelarrangement vof split gears,- an yasso-1 ciated ai speech change-v indicator furnishing tlie L ,Y operator ,with ".fint'ori'nation: yas to; I thev exact condition of thezsplitligears so that hei not attempt fnianipulatioiioi the shii't leverfatalair-inappropriate.tiniexpi` af @ther objects f andadvantages appear in, thetnfollowfing specification; referencey .beinguy had Lito the a accompanying drawings, in Whrelrnl A f Figure 1v iis aisectional#perspective View of am speedschangex: mechanism L constructed in accordance With-the:- invention, the inechanisniubeingztin lowzfgea'r. l f l Fignrea' :is central. longitudinal f section ot the":inechanism,A again y"in loivgear. oiFigure;liisifa detail perspective View of the itrao-k assembly-i :iL-f1 a z Figiure #1 isla sectional diagram showing therpai-tslin lonT gear; 1 v n v Figure rfisifa idiagram 'illustrati-ng the a'ot ot' sliifting'fronii lwfto intermediate ge'ai-'.='

mFigure Gis a diagram illustrating the poy sitionioff` the.y parts after intermediate gear hasfbeen-reachedf he; 1 Y i Y Figure gis. a'fdiagraniillustrating the `act of shitting from .intermediate to "highy gear. illigure' Swislai diagram illustrating the Vpofligulre V9 detailr .perspective view of one ot'the tracklassembly.-cylinders. fEiguretlOis a side elevation ot one ot the trackidiscsf- Figure 1,1 is: a detail perspective View of oneofwthe split gearblocks. :1I1`ig`liie` 12de afdetail perspective view oiE the shittnods and gear block carriage.

Situated-in theltransmission oase 1 is the counterslmttf:9J which `is fround at 3 and nonF` circular at 41;. The counter-shaft rotates con- SPYEED-CHAIYTGE MECHANISM.

17, 1925. Serial No.l 56,971.

tinuo'usly Wlieiifthe cluth'v 5*?(see Figures 1 and 2)"is"shifted-either into engagement-with the driven gear'o orxthe-driven pinion 7".' Motion is derived from the crankshaftv 8 of the 'engineA (not shown) and poweristaken 011' at the "transmission sliattj) which extends to 'dierential gearingl (not shown) at the reaiul 1 f w'llhej driven gear (i has a pinion '10* Which niesli-e'swithz an Aidler 11E frlhegeais and" areiloosefupon the shaft Qian'd arerevoluble upon sleeves- 121and 12a. Both geai'slievolve continuo usly F buty in opposite 5 directions.` Uponsliitting the clutch :leven lfforivardly the clutch 5 is i'novedi into engagementwith the gear (ig-The gear-''is `thenSfse'cured to drivesthe countersl-ia-it by nieans ofvr the drive pinion 14k. Upon shifting the lever 13' rearwardly Athe clutch is' brought into engage-*J nient' .with the 'driven `pinion 71s@ *that 'the direction oi' turning v`of the fcoui'itershaft 9L is reversed. iThe movements of the lever 13 aretransinitted by means ot'a link l'to the clutch` forki 16. lrblaedal' (Snot shown)` may be substituted for dthellever 131 l Secured in Athe, transmissionfcase?1`fbvv nieans 'of bolts 17 so ithatit'can notjinove in'f any respect is Vthe-track Af'asjseiiiblyl (Figs 1 and J3)socalled becausef 'it isA coinfposed of'a'nfasseinbly ofcyli'nders 195205 The various disksi'iif the order'nainedandY1 shown, are Arepresentaltive ot ii'rst,seco`nd and third' speeds; The' 4rever-eef"Speed is handled by theclutch lever135` and the n'iotor ve# hicle may be driven in* reverse at any one of the three speedslprovided tor-.fw One of the cylinders 19'is`sliown in'det'ail in Figure 9; "All'four are alike. The cylinder has' a pair ot groovesland 127. 1A cle-"- tail lot one ofthe` three track disksis shown in Figure S10.` vThe disk 23 is vinadef of "rela# tively thin springv steel or-brass,beingpro#` vided lwith -gi'oovesQSand Q-Qfniatching the grooves Q61 and 27 fwhen z'isseinbled. The'V disk also has a-senircircularcut 30 pi`odn'c'` ing` apportion of metal which;'afterfdivision tongues 32 andBS Upon fitting the various cylinders and diskstogether (Figs. 1 and i of continuous grooves in thetop.

Shift rods 311 and-35 occupy :the'g'rooveslfI The shift rods are held in place bylvirtiie'otl the fact that they pass under the tongues 32 and 33 of the various track disks. It is ol served that the track disks are of a diameter greater than the adjacent cylinders 19, 20, etc. rl`he arrangement leaves the tongues and 33 exposed at the periphery of the cylinders. rEhe tongues and 33 being flexible and free to the extent of 18()o of the circumferenceA of the respective track dif are capable of being bent out of cireuniterential alignment by means of the shift rods 3l and 35. Upon such occurrence the track disks assume the dotted line positions in Figure 3, presenting` in part the appearance et a spiral.

For the purpose of bending the tongues 32 and 33 of the track disks, the shift rodsll and 85 each carry a set of three shift pins 3G and 37 (Fig. l2). These are split at 33 to receive the ends of the tongues. The shift rods are provided with racks 39 in confronting locations. A shift pinion i-0 meshes with the racks. The pinion is carried by a shift lever Ill which has bearing both upon the first cylinder 19 and in other parts of the structure terminating` in a handle aecessilde by the operator. Upon turning the slnft lever in the counter-clockwise direction. (arrow a, Fig. 3) the shift rod 35 is made to move forvv'ardly and the shift rod ill rearwardly. The extremity ot the tongue SEB it disk 23 is then brought into alignment with the extremity7 of tongue 32 of disk 'lhc saine is true of the disk in respect to the disk rlhe result is the provisionL of a cross-over track from one disk to the other. The arrangement resembles a spiral as designated by dotted lines (Fi 9).

A pair of guide rods 42 and 43 have flanged rollers 44 and 45 riding upon one ot' the track disks. ldlhen the mechanism is adjusted for low speed, the rollers'ridc upon the low speed track disk 23. ff le the tongues are bent as previously7 described, the rollers all and 4:5 will ride upon the resulting cross over track to the second disk 2-1 upon which disk they will subsequently ride while the mechanism stands in second speed position. Similarly. the rollers are capable of ridingacross and upon the disks when the mechanism stands in the high speed position. lt is by means ot' this riding of the rollers lll and 45 that the guide rods are either shifted longitudinally or made to occupy predetermined positions.

The longitudinal movements of the guide rods 42 and 43 are solely for the purposeof shifting the gear blocks 4G and et?. These blocks are made in halves (Fig. ll). rlhey have central grooves 48 corresponding` With the non-circular portion '-is of the countershaft so that they are compelled to turn with the counter-shaft but at the same time are capable of longitudinal sliding movement when demanded by the guide rods. The ends of the guide rods are iiXed in the duces a rigid carrying structure which not only supports the gear blocks in proper relationship but provides an adequate carriage upon which they may ride. The gear blocks have holes through which the pairs of carriage rods p: 1s. The gear carriage revoluble vvith the counterslnift but incapable of longitudinal movement.

Provision is made tor the prevention of operation of the shift lever tl while the rollers -i-f-l and l5 are traversing the space betvveen track disks during the shittingr ol the gear blocks. Pcndent from the right. extremities of the shift rods fl-l and are lock pins and 55 vvhich coact with diametrically opposite pairs of lock lugs 5f; and TT on the disk rlhese lugs are spaced to form central channels 5S and when the lock pins :it and V15 are in circuml'erential alignment they ride through the chanimcls 58 each time the lock lugs pass the pins are traveling from one disk to the other. lt 1s to be noted that the guide rods l2 and i.t3 are situated directly over the lock lugs and the locking function of the lugs 5G and 527 in respect to the rods 3l and 35 is therefore bound to occur while the rollers 3J.V and travel over the split tongues from one disk to the other. ln practice the lock pins 5ft and ivill be fitted with rollers` so that there may be no unnecessary friction.

.tl speed change indicator provides a visual indication of the position of the gear blocks #tti and -il-'T within the case '1. The indicator comprises a dial 5f) situated in some convenient place before the operator. The dial is stationary and is divided into segments (i0, (5l and (S2 with intermediate red segments (S3. The dial is traversable by i, pointer G-l carried by an indicator shaft $5 which extends through appropriate bearings into the transmission case l, where it carries a pinion (3(3. The pinion meshes with the rack surface 6T of an indicator' rod GS that is appropriately guided at (39. 'lhe guide rod carries three studs 70. These studs are intended to run in the spaces Tl other.

rFigure 4 is a"diagrainiiiatioillustration of theparts` while in low speed position. y In Figure 5 `the toiig'u'es and 32 are'shown" andi ,772i hetiveeii the low," seooiid and third andv 47. The gea-rs are" split, this 'heiiig'the character ot the' blocks themselves; but whenA properly assenihled-`` constitute i gears: Thev'arioiis' positions oit' thestuds Complete T() iii' respecty to the gears' are best seen iii `l-"ig'iires t to 8 inclusive. lThe studs 2idvaiiee iii` respect'k tot the' gears as the prof gressi-v'ely higher speed-Changes are nude',-

ii'ismis carried; rThe free tongues@ and 33 of the various track disksl 23,72% and`i25 are in oir'ounifereiitial aligi'iineiitnia'lingcoini plete: dislsgsoto speak: The gear blocks' lo andfli? are revohihle) with the' Counteri shatQ and'lth'e rollers 44;" and i are ridingI upoiivtlie" loiv speedl track disk' 28. The

tongues of the various disks are' heldin any giveii positionlhy theshittrods 3s' audf which* have split pins 36 and' 37 (Fig. l2) in vliioh/` the-,various tonguesare held.

movement of tliesliittleveiil inth'e coun-` teroloolnvise'direction (ai'r'oiva, Fig. 3) iviil produce a :to'rivaril nioveiiientf of the rod 35 ainda rearwardiiiovemeiit ofthe rod 34' to 3 such* extent" that. the right tongues 33' are bent forwardly suiiieie'ntly far tov meet the lefttongues 32' ivliioh are heiit'reaiwaidlyf to* agree' 'and' Complete' Cross over tra'elrs see Fig; 3) troin oneE disk" to the" dotted lines,L

heiit' as stated.'` The roller 44E* has ridden "halt Way upfthe cross over vtraelrand has partlyshifted tliegear'hloek'fi in the'direo- I tion of the iiiteriiiediatespeed Apositionl By the tiine vthat the roller 44 has traversed the otherhalt offtheicrossover track aiidhas startedto ride upon the second disk Qiithe roller w'ifll'hegin to riihefuponk the 'afore' said'eross over tra'elrtorthe purpose oi' ooi-` respondiiigly shifting," the gear bloei;` 47.

The block wvillhave 'reached its 'ul'tirnate second speed' position; andthe block will' follouv 'iniiu'edia'tely thereafter so that the gea-r blocksassuniethe position in Figure '6;

T he gear T3 Will iiolonger engage"thpinioii" .76 hut 'the "gear 7%" will hein engagement 55'" ywith the second speedpiuioii T7.

The transmission shaft 9 has pinions 7o,y 7?"aiid 78 Corresponding with` Sion= shaft; 9

f seen in 'Figui'es 4to" 8 inclusi;

'A it tothe position shown in 'Figure'fl 1ivlie i y u i f *i mi', limo-torni they tansniissioi'i shaft 9 drngthe Shifting ot the blocks` 46, andi? betweefn ny O i frein low to second speedthe se til 11""3l niet@ pi Figure `up'on A" shittii-rgf i of r1 by nieaiis 'oi' the lever 4l" as 'already stat As soon as the operator does t pointer' 6`l"lias`cleared" `the ytir'st redl'lsegineiit 9U and lias reached thel seofoiidfu'liitefsegiiient oil he ina'ysately return tlieshii't'lev'ei Alfth the:

original position` thereby' bend ig' theVVA tonguesv 32" and haokitofthe'former eireul1 L lar formation". The' look pins"54"a1id'5q 71h95' thenk assume the 7 former i'rouiii" alignment and 'ride'iii' the Central Chann l ofthe'loc'k disk"52'When'the'lugs 56 ai d repetition of' the desorption' need' iihtjliif giif'en. The fi'eader will" uiidelistajii When the'liibli'speedposition isfa will "he the gearo that the ltraiisnvlis i through then high speed pin `As"stated*beftore, the indicator 1,is opeiat 7 by"th`e iiidieator yrod'f 68'a`s'tl1e' studs TO nieve intoth'ef various' 'spa'es '7 ,1 and?? 110' Th sid" get intonthe"'various spaes th's nianiier Vheii the block' 46 "is inade" to' y chan "e iii'positioniroiiithatillustra ed iii'Figu l toi that 'shoyvnin Figure Gf byfii'ieaiisfot lth p assagefof" the roller ifi-olii' low spe lf track 23'to intermediatespeedftraeli ifi' th: l blocl`-`iiio`ves`forwardlyivith thewi'od u with and engages inthe groove` 7l gear hloolll, when thatfblook h oross` `ove'r Yfrom" loi'v to iiiterni'ediLt lolock` their inoves said arm 68, 'fofrivg it remains until anotl'ier'shitt is iii'ade.

F igure" S' Thesafiiie'l"proess"riooiun, v H shitting vfrom high to l o\v`, gear, ugh is the iiiotioii'vill'theirhe"iii'the opposite 'diijeo- 130 35. it is intended to lock the shift rods only wliile the rollers del and are immediately approaching, passing over or immediately leaving the cupped oints in the guide tracks so as to prevent the possibility of the rollers getting off of the tracks While the same are being shifted. Excepting as otherwise indicated, the shift rods can be moved at will, but such movement should not occur While Athe rollers are in the vicinity of the cup joint, it being then that the pairs of lugs on the lock disk function.

W'hile the construction and arrangement of the improved speed change mechanism is .that of a generally preferred forni, ob-

Vviously modifications and changes may be made without departing' from the spirit of the invention or the scope of the claims.

I claim l. Speed change mechanism comprising a continuously revoluble engine shaft, a counter-shaft continuously driven thereby, a transmission shaft having pinions, a gear block composed of sectional gears mounted upon and continuously driven by the countershaft, and means to alternately shift the gear sections to progressively advance the gear block along the countershaft to engage, various ones of the transmission shaft pin- -ions thereby to drive the transmission shaft at various speeds and shift from one speer to another without disconnecting' the conntcrshaft from the engine shaft..

2. Speed change mechanism comprising a continuously revoluble engine shaft, a countershaft continuously driven thereby, a transmission shaft having a plurality of pinions of different size, a pair of gear blocks carried by the counter-shaft including a plurality of gears of different size, and means to independently shift the gear blocks along the counlershaft so that one of the gears of one block departs from a previously engaged pinion simultaneously With the engagement of another' gear of the other block with another pinion thereby avoiding an interruption of the motion and permitting shifting from one speed to another without disconnecting the countershaft from the engine shaft.

3. Speed change mechanism comprising a continuously driven countershaft. a. transmission shaft With pinions to be driven. split gears constituting blocks carried by the counter-shaft, 'supports carrying rollers extending from each of the blocks, and tracks upon which the rollers run thereby to hold the gear blocks in predetermined relationship with said pinions.

4f. Speed change mechanism comprising a continuously revoluble countershaft, a transmission shaft having pinions to be driven, split gears carried by the conntershaft constituting blocks, supports extending from said blocks carrying rollers, relatively stationary tracks in concentric arrangeinent on which said rollers run to hold said blocks in predetermined relationship and the gears thereof in alignment to mesh with certain pinions, and means to move portions of said tracks thereby to make connection from one track to another causing said rollers to cross over upon a. succeeding track and shifting the blocks so that the gears thereof mesh ivit-h other pinions on the transn'iission shaft.

5. Speed change mechanism comprising a continuously rcvoluble countershaft, a transmission shaft having pinions to be driven, split gear blocks carried by the countershaft constituting complete gears when appropriately assembled to drive said transmission shaft., rollers supported upon said blocks, relatively stationary concentric tracks upon which said roll-rs run, thereby holding said blocks to complete the gears, flexible tongues included in said tracks, and means to so flex the tongues as to establish a cross over connection from one track to another causing the rollers to cross over and thereby set the blocks so that driving of the transmission shaft occurs through other combinations of gear and pinion.

(5. Speed change mechanism comprising a continuously revoluble countershaft, a transmission shaft having pinions to be driven, a plurality of gear blocks carried by the counlershaft, rollers carried by the gear' blocks, a track assembly comprising alternate cylinders and track disks which have flexible tongues, shift rods having connection with said flexible tongues holding them in such manner as to keep the track disks in concentric relationship, so that the rollers may run upon any one thereof and keep the gear blocks in predetermined relationship with the pinions, and means to shift said rods thereby to flex the tongues and establish cross over connections from one track to another, said rollers thercby crossing over to another track and correspondingly shifting the blocks to establish another relationship thereof with said pinions.

'i'. Speed change mechanism comprising a countershaft, a transmission shaft having pinions to be driven, a carriage associated and revoluble with said countershaft, gear blocks mounted upon the carriage to mesh with the pinions, and means to first slide one of the blocks then the other upon the carriage along a conntershaft to cause meshing of the gear blocks ivith the different. pinion producing a different driven speed at the transmission shaft.

8. Speed change mechanism coniprising a countershaft, a transmission shaft having CTI ,disks providing continuous grooves along the track assembly, shift rods occupying said grooves and having means including pins holding said tongues, and means to shift the rods-inpopposite directions thereby lto flex the tongues to such extent as to provide cross overs from one track to another causing a corresponding action' of said rollers and a shifting action of said gearblocks in respect to the transmission shaft pinions 9. Speed change mechanism comprising a countershaft, a transmission shaft `having pinioiis to be driven, a carriage mounted on and ievoluble Witlithe countershaft, split gears constituting gear blocks mounted upon the carriage, rollers carried by the gear blocks, a track assembly comprising alternating cylinders and track disks, flexible tongues including in said track disks, regis-V tering grooves inl the cylinders and track disks providing continuous grooves along the track assembly, shift rods occupying said grooves and having means including pins holding said tongues, means to shift the rods in opposite directions thereby to flex the tongues to such extent as to provide c.

cross overs from one track to another causing a corresponding action of said rollers fand a shifting action of saidrgear blocks i'nlrespect to the transmission shaft pinions, and means associated with said gear blocks providing aV visual indication of the shifting of Saidblocks along the cai'riage.

10. Speed change mechanism comprising a countershaft, a transmission shaft having pinions to be driven, a carriage mounted on and revoluble With the counteishaft. split gears constituting gear blocks mounted .upon the carriage, rollers carried by the gear blocks, a track assembly comprising alternating cylinders and track disks, flexible tongues including in said track diskspregis- Vtering grooves in the cylinders and track disks providiiigV continuous grooves along the track assembly, shift rods occupying said grooves and having means including pins holding said tongues, means to shift the rods in opposite directions thereby to Vflex the tongues to such extent as to provide cross overs from one track to another causing a corresponding action of said rollers and a shifting'actioii of said gear blocks in respect to the transmission shaft pinions, indicator means including a calibrated dial and pointer, and means to inove said pointer across the dial to furnish a visual indication of the condition of said gear block, said means including an indicator rod, studs which are engage-able with the gears of said blocks.

ll. Speed change mechanism comprising a countershaft, a pair'of blocks having gear ysect-ions forming complete gears when the blocksare in registration, a carriage revolving with the countershaft upon which the blocks are mounted, rollers carried by the gear blocks, a shiftable track assembly causing relative movement of the blocks along the carriage so that they may assume different registering positions therealong, and means associated with said'carriage and track assembly preventing erroneous sliifting of the track assembly during the period of relative movement of the blocks While performing a shift.

l2. Speed change mechanism comprising 'a countershaft, gear blocks comprising gearY sections making complete gears when the blocks are in registration, a carriage revoluble with the countershaft upon which the blocks are slidable)` a lock disk constituting one terminal of said carriage and including pairs of lock lugs defining a central circ'uniferential channel, rollers carried by the blocks, ti'ackcrdisks upon which the rollers run including' flexible tongues, shift rods to flex the tongues, providing cross overs from one track to'another causing a correspond-V ing action of said rollersl and a .relative shifting of said gear bloc-ks so that they assume Vanother registering position along said countershaftl` and lock -pins carried by said shift rods then'assuining positions to the outside of said lugs, thereby preventing erroneous shifting of the rods While said tongues are flexed and said gear blocks are `undergoinga shift.

WILLI-AM M. MITCHELL. 

